The well-being of children in same-sex families is debated in contemporary policy, law, and public realms. Yet, due to data and methodological limitations, we know relatively little about the mental and physical health of the approximately 220,000 children who live in same-sex families. Additionally, research on different-sex families shows that family resources are a central mechanism shaping child health, yet the role of family resources has gone unexamined in research on same-sex families. There is urgent need to resolve the question of the basic relationship between same-sex family structure, resources, and child health because the current state of in- conclusive research in this area may result in ineffective, misguided, or harmful public policy that reduce the effectiveness of initiatives aimed to promote optimal child health as well as undermine future scientific research in this area. The overall objective for this proposed project is to determine the population-level relationship between same-sex family structures, family resources, and child health. Our central hypotheses are that children residing in same-sex married and cohabiting families will experience worse health when compared to different- sex married families due to same-sex family's lower levels of family resources; children in same-sex families will experience similar health when compared to different-sex cohabiting and single-parent families due to similar access to family resources. The rationale that underlies the proposed research is that the development of consensus regarding the relationship between same-sex family structures, resources, and child health will direct future definitive research and public policy on the underlying contributors to optimal child health. The central hypothesis will be tested by analyzing pooled cross-sectional nationally representative data from the 1997- 2012 waves of the Integrated National Health Interview Surveys in pursuit of the following specific aims: Aim 1. Examine differences in children's physical and mental health across same-sex married, same-sex cohabiting, different-sex married, different-sex cohabiting, and single-parent family structures. Aim 2. Examine the role of family resources (i.e., socioeconomic, parent health and health behavior) in contributing to child health differences across family structure. Results are expected to be significant by filling a fundamental gap in our under- standing of the relationship between same-sex families and child health with reliable and valid nationally- representative population-based data. The proposed research is innovative because it takes a substantial departure from previous research by utilizing 1) national population-based data, 2) reliable and valid measures of same-sex married and cohabiting families, 3) comprehensive measures of family resources, and 4) multiple dimensions of child health. Results from this proposed study are expected to provide the focus for, and support the feasibility of, a subsequent mixed-methods longitudinal R01 proposal that will examine how demographic (e.g., race), relational (e.g., family transitions, length and quality), contextual (e.g., community resources),and selection characteristics determine child health in same-sex family structures.